Boring machine



FIG. 1 is a front view of a boring machine according to the design of the present invention;

FIG. 2 is a back view of the boring machine;

FIG. 3 is a plan view of the boring machine;

FIG. 4 is a bottom view of the boring machine;

FIG. 5 is a left side view of the boring machine; and,

FIG. 6 is a right side view of the boring machine.

The broken line showing of the boring drill is included for the purpose of illustrating portions of the boring drill and forms no part of the claimed design. 

The ornamental design for a boring machine, as shown and described. 